In context of training your bayonet lug may not be bad. I have packed a 590a1 on a few occassions. They did not teach me much about using a mounted bayonet so, my reasoning is based on my lack of experience in using one and the fact that anyone with no experience has no business trying to use one.
I figure I'm still alive today because of Marines on a few occassions so the respect goes both ways. If faced with a scenario of a home invasion like the one you describe, I'd rather have a high capacity side arm to fall back to than a bayonet. Or have more shells onboard and the practice to get rounds back in it to keep it running. Combat reloading and speed reloading could have kept that guy alive if he went to "failure to stop" mode after hitting body armor. Head shots would have probably stopped the fight. But most Marines would have buckshot instead if bird shot as well.
Thank you for your service as well. The Marines are some of the most respected heros our nation has in my eyes.